Control of superconductivity with a single ferromagnetic layer in niobium/erbium bilayers

Abstract

Superconducting spintronics in hybrid superconductor/ferromagnet (S-F) heterostructures provides an exciting potential new class of device. The prototypical super-spintronic device is the superconducting spin-valve, where the critical temperature, $T_c$, of the S-layer can be controlled by the relative orientation of two (or more) F-layers. Here, we show that such control is also possible in a simple S/F bilayer. Using field history to set the remanent magnetic state of a thin Er layer, we demonstrate for a Nb/Er bilayer a high level of control of both $T_c$ and the shape of the resistive transition, R(T), to zero resistance. We are able to model the origin of the remanent magnetization, treating it as an increase in the effective exchange field of the ferromagnet and link this, using conventional S-F theory, to the suppression of $T_c$. We observe stepped features in the R(T) which we argue is due to a fundamental interaction of superconductivity with inhomogeneous ferromagnetism, a phenomena currently lacking theoretical description.

19 pages, 4 figures

References in corpus (7)

• Superconducting Spintronics
• Evidence for Triplet Superconductivity in a Superconductor-Ferromagnet Spin Valve
• Superconducting triplet spin valve
• Controlled suppression of superconductivity by the generation of polarized Cooper pairs in spin valve structures
• Angular dependence of superconductivity in superconductor / spin valve heterostructures
• Isolation of proximity-induced triplet pairing channel in a superconductor/ferromagnet spin valve
• Unanticipated proximity behavior in ferromagnet-superconductor heterostructures with controlled magnetic noncollinearity

Cited by in corpus (3)

• Generalized quasiclassical theory of the long-range proximity effect and spontaneous currents in superconducting heterostructures with strong ferromagnets
• Superconducting spin valves controlled by spiral re-orientation in B20-family magnets
• Proximity effect in [Nb(1.5nm)/Fe(x)]${}_{10}$/Nb(50nm) superconducting/ferromagnet heterostructures